Influence of WEC geometric variables on the performance of an integrated WEC–VLFS system

This study proposes a novel integrated concept that combines a wave energy converter (WEC) array with an interconnected very large floating structure (VLFS), aiming to provide a solution capable of harvesting wave energy while simultaneously protecting offshore structures. A numerical model of the integrated system is developed using the discrete–module–beam (DMB) method together with the Lagrange multiplier technique. After validating the accuracy of the simulation approaches, the influence of WEC geometric variables on the system performance is evaluated, including the energy capture performance of the WECs and the hydroelastic response of the VLFS. Five WEC geometric variables are examined: length, gap, number, draft and shape. Due to the complexity of the analytical model, deriving an optimal damping coefficient for the power take-off (PTO) device is challenging; therefore, it is determined through numerical search. A series of simulations show that, compared with the other four variables, the integrated system is most sensitive to the WEC length. Moreover, incorporating the WEC array effectively reduces the hydroelastic response of the VLFS, particularly under short-wave conditions. In addition, within a three-unit WEC array, the central WEC exhibits a significantly higher power capture efficiency than the side units. The methodology and findings of this study can provide useful insights for the preliminary design of similar integrated systems. • A novel integrated WEC-VLFS system is proposed. • DMB method and Lagrange multiplier technique are adopted to develop the numerical model of the integrated system. • Numerical search method is utilized to determine the optimal PTO damping. • A comprehensive study concerning the WEC geometric variables is conducted on the performance of the integrated system.